1. Field of the Invention
This invention relates to mechanical movements for converting rotary motion to gyratory motion in which the motion is changed by means of unbalanced weights and in which the motion is changed by means of inertia or centrifugal means.
2. Description of the Related Art
A number of patents on inventions using unbalanced weights to impart vibratory motions appear in the U.S. Patent records. U.S. Pat. No. 2,730,237 discloses a vibrator for screens which uses an unbalanced weight on each end of a rotary shaft. U.S. Pat. No. 3,404,854 describes an apparatus with a rotating frame which has a bore through which a rotary shaft bearing a weight passes. U.S. Pat. No. 3,505,886 describes a hammering vibrator in which the weight is driven by an eccentrically located crank through a lever. U.S. Pat. No. 3,810,394 describes a centrifugal mechanical device in which an off center of rotation axis shaft with crank arms is used to vary the distance of rotating masses from the off center of rotation axis shaft. U.S. Pat. No. 3,998,107 describes the use of a crank-like shaft to vary the radius of gyration of multiple gyrating masses. U.S. Pat. No. 3,220,268 describes a vibration generator with eccentric masses which rotate in parallel planes and which may rotate at different speeds. U.S. Pat. No. 4,289,369 discloses a vibratory force producer in which multiple plates bearing unbalanced weights rotate in a single plane.